This invention concerns actuators for remotely controlling operative mechanisms, and specifically relates to an improved motorcycle throttle control unit for mounting on the handle bar for actuating the carburetor disposed beneath the motorcycle seat.
Motorcycle throttle control units of the prior art have generally taken the configuration of a rotatable drum on which the inner member of a Bowden cable is connected. Upon rotation of the drum, the Bowden cable member wound onto the drum to effect relative movement between the cable members and consequent control of the carburetor. The outer member of the Bowden cable was generally abutted against the housing of the control unit and the drum was rotated in union with the twist-grip handle. The cable members joined the unit at a right angle, generally, and were thus exposed to wear and breakage.
These prior art throttle control units have the characteristics of being mechanically severe in action upon the inner throttle cable causing it to stretch, to deform, and often breaking individual cable fibers. Further, the prior art constructions were limited as to the rate of control that could be effected by rotation of the twist-grip handle and it was not possible to coordinate readily the rotational movement of the handle to the performance curve of the engine to achieve, when desired, a uniform correspondence between degree of handle rotation and power output of the engine as controlled through the throttle opening. The prior art control units were basically of similar construction irrespective of the vast different scales of performance achieved by the various motorcycle engines for which they were installed, and consequently very little attention was paid to adapting the throttle control twist-grip to function in a specific manner for a specific type of motorcycle engine.